Pressure sensors often include a pressure sense element that is configured to detect a pressure of a media to be sensed by converting mechanical stress caused by the incoming pressure of the media into an electrical output signal. Pressure measurements are typically taken in the context of absolute, gauge or differential (or relative) pressure measurements. An absolute pressure sensor measures a pressure relative to a vacuum (or near vacuum). A gauge sensor measures a pressure relative to atmospheric pressure. A differential pressure sensor measures a pressure difference between two pressure inputs. Pressure sensors are used in a wide variety of applications including commercial, automotive, aerospace, industrial, and medical applications, among other similar and dissimilar industries.
A common method for field calibration of such pressure sensors includes the “shunt calibration” method. This method typically applies a known, accurate resistance across one leg of the pressure sensor transducer, which simulates an actual physical stimulus when one is not present. Upon application of this shunt resistance, the output of the pressure sensor transducer changes as it would if a known pressure were applied. The shunt calibration method has some shortcomings. For example, in order to achieve the most accurate results, the value of the shunt resistance should be tailored to and depend on the particularly characteristics of the pressure sensor at hand. In some cases, the value of the shunt resistance may be calculated from calibration data derived from the particular pressure sensor. However, the selection of a shunt resistance value during calibration of the pressure sensor tends to increase the complexity of calibration and assembly of the pressure sensor, since various values of shunt resistors must be stocked in the factory, and since only a limited number of resistance values can be stocked, an ideal shunt resistance value will often not be achieved. What would be desirable is an improved system and method for shunt calibration of a sensor.